Many patent applications are filed domestically and abroad which relate to a patient transfer apparatus for transferring a patient between a patient-moving bed and a patient bed. Many filed and registered domestic and foreign patents use very complex devices or power-transmitting devices and thus a using procedure is complex and expensive facilities are required, so that the patents are not easy to practically apply. U.S. Pat. No. 4,259,756 and KR 10-2002-0049632 etc. are relatively simple in structure and convenient in installation and operation, but suffer from a disadvantage that when the patient lies on a top movable board of the patient transfer apparatus, a great frictional force occurs between the top movable board and a mattress of the patient bed due to the weight of the patient and thus the top movable board is difficult to easily move. To overcome such a disadvantage, U.S. Pat. No. 7,000,268 newly installs transfer arms which allow the top movable board to easily move over the patient bed. However, a complex step is required of separately installing and withdrawing the transfer arms. KR 10-2003-0037260 shows a structure where a belt-type top movable board is moved over the patient bed and the patient's body on the top movable board is also moved together according to movement of the belt. At this time, a distance over which the top movable board is moved over the patient bed has to be longer than a distance over which the patient's body on the top movable board is moved; rather, the distance over which the patient's body on the top movable board is moved is two times the distance over which the top movable board is moved over the patient bed; therefore, practical application is difficult.
According to KR 10-2009-0053325 devised by the applicant, the top movable board can be easily moved over a little longer distance over the patient bed through the transfer arms and a wheeled chassis movable on the transfer arms. In the present invention, instead of the wheeled chassis movable on the transfer arms, a side protector of the patient transfer apparatus is laid on a mattress of the patient bed and the transfer arms are moved over the side protector, whereby the top movable board loaded with the patient's body can be easily moved over the patient bed.